Comparative analysis of the influence of construction methods and consolidation waiting time on the behavior of diaphragm walls in underground structures

Abstract

In major urban areas of Vietnam, rapid economic development and population growth have caused surface space to become overloaded, promoting the trend of developing underground structures such as basements, underground parking lots, underground shopping centers, and underground transportation systems. However, the construction of these structures leads to the appearance of numerous large-scale deep excavations in complex geological conditions (weak soil, high groundwater level), posing significant technical challenges related to diaphragm wall stability and overall structural safety. This study applies the finite element analysis method using PLAXIS 2D software to simulate two common construction methods, Top-down and Bottom-up, under conditions that take into account time-dependent factors and the soil consolidation process. By performing staged construction analysis combined with a drainage mechanism, the study quantitatively evaluates the impact of the construction method and the consolidation waiting time between stages on the working efficiency and structural stability of diaphragm walls.